Diaphragm device



Nov. 23, 1965 R. E. KALERT, JR

DIAPHRAGM DEVICE Filed Jan. 16, 1964 FIG.3.

INVENTOR. RALPH E. KALERT JR.

AGENT United States Patent 3,218,978 DIAPHRAGM DEVICE Ralph E. Kalert, .lr., Granite City, Ill., assignor to ACE Industries, Incorporated, New York, N.Y., a corporation of New Jersey Filed Jan. 16, 1964, Ser. No. 338,175 Claims. (Cl. 10344) This invention is directed to diaphragm devices and more particularly to a diaphragm device having a diaphragm adapted for fitting between two portions of the device.

This invention is particularly adapted for use with pumping units, for example. Small inexpensive diaphragm fuel pumps have been devised which can be added to the fuel system somewhere in the fuel line between the carburetor and the source of fuel. Examples of such diaphragm fuel pumps are disclosed in applicants copending application Serial No. 220,638, filed August 31, 1962, entitled Fuel Pump, and copending application Serial No. 239,898 of Eldon A. Johnson, filed November 26, 19 62 and entitled Fuel Pump, the entire disclosures of which are incorporated by these references. Such fuel pumps consist of a small diaphragm forming a pair of chambers within a housing, one on either side of the diaphragm. One chamber is connected directly to the crankcase of the internal combustion engine, if it is a twocycle engine, or to the intake manifold in a four-cycle engine installation. The other chamber in the housing is the pumping chamber for the fuel and is connected through check valve passages to the source of fuel and to the carburetor. Pulsations provided by the engine during operation reciprocate the pump diaphragm to pump fuel from the source into the carburetor.

Air pressure pulsations are created in the crankcase by movement of the piston back and forth to provide positive and negative pressures in the pumping chamber. For example, on the intake stroke of the piston, the air in the crankcase is compressed and provides a positive pressure to drive the pump. Upon the exhaust and compression stroke of the engine, negative pressure is created in the crankcase and provides the suction required to move the pump diaphragm in a suction stroke. Thus, the diaphgram flexes back and forth upon intake and exhaust strokes of the piston. The pump structure is formed of a pair of interfitting body members which are merely snapped together to clamp or grip a diaphragm positioned between the two body members. The body members are formed with matching or mating portions and this enables one member to be rotated relative to the other about a common axis allowing the pump to be adapted to any carburetor without requiring a specific fixed arrangement of the inlet and outlet nipples for each particular installation. The diaphragm must be tightly sealed and gripped about its marginal portion when the two interfitting body members of the pump are snapped together.

It is an object of the present invention to provide a diaphragm device in which a flexible diaphragm provides a seal between two interfitting portions of the device.

It is a further object of the present invention to provide a pulse fuel pump for either a two cycle or a four cycle internal combustion engine, in which the flexible diaphragm is easily sealed and gripped.

A further object of the present invention is to provide a diaphragm device having a diaphragm fitting between two clamping portions with the portions arranged for relative movement and the diaphragm easily gripped and held in sealed position without the necessity of any separate securing means or gasket.

Briefly described, the invention comprises a diaphragm "ice device having a pair of interfitting body members with one of the body members being cup-shaped and having an outer annular rim and an annular shoulder adjacent the rim forming a seat. the other of the body members having an annular extension telescoping within the cup-shaped member and adapted to be disposed adjacent the annular shoulder, and a circular diaphragm positioned across and sealed along its marginal portion between the annular extension and the annular shoulder, the annular seat and the annular extension having complementary oppositely facing generally smooth and generally parallel surfaces each interrupted intermediately thereof by an annular groove, the diaphragm being positioned across the grooves and deforming into each of the grooves upon gripping or pressing of the diaphragm between the smooth surfaces of the annular seat and annular extension thereby to seal and secure the diaphragm. Other objects and features will be in part apparent and in part pointed out hereinafter.

The invention accordingly comprises the constructions hereinafter described, the scope of the invention being indicated in the following claims.

In the accompanying drawings, in which one of various possible embodiments of the invention is illustrated:

FIGURE 1 is a plan view of a fuel system comprising a carburetor attached to the manifold of an engine with the novel pump of this invention installed on the carburetor and connected to a source of fuel;

FIGURE 2 is a sectional view of the pump of FIG- URE 1 showing the pump mounted on the carburetor;

FIGURE 3 is a sectional View taken generally along line 3--3 of FIGURE 2;

FIGURE 4 is an enlarged fragment of FIGURE 2 showing means for gripping and sealing the marginal portion of the diaphragm; and

FIGURE 5 is an enlarged fragment of FIGURE 4 with the diaphragm removed.

Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.

FIGURE 1 discloses a diaphragm device embodying a fuel system for a four-cycle operation. A carburetor indicated at 10 is mounted upon the intake manifold M of an internal combustion engine E, which, for example, is a four-cycle engine. A fuel pump 12, in accordance with the invention, is mounted on the carburetor and is connected by a flexible tubing 14 from a nipple structure 16 to a fitting 18 to provide an air conduit between the engine intake manifold and pump 12. Another laterally extending nipple structure 20 is 1 connected by fuel line 22 to a source of fuel, such as a fuel tank 24 schematically shown. The carburetor may be of a well-known type and consists primarily of a tubular air and fuel mixture conduit 26 attached by a flanged end 25 to the engine manifold, such as a stud 28 extending from the engine block. At the other end, an air filter housing 30 provides an opening to the mixture conduit 26. Within the filter housing 30 is a porous filter for removing dust and other particles from the air entering the carburetor. Rotatably mounted within the carburetor are a throttle valve structure 32 and a choke valve structure 34 to control the flow of air through the carburetor. Other details of the carburetor are well known and are not illustrated.

Carburetor 10 is operated in a conventional manner to permit air flow into the engine manifold and to mix with the air a controlled amount of fuel to provide the proper combustible air and fuel mixture. Details of the fuel pump 12 are shown more specifically in FIGURES 2 and 3. Pump 12 consists essentially of a pair of interfitting oppositely facing cup-shaped body members generally designated 36 and 38. Upper cup-shaped member 36 has an annular extension 40 forming an inner rim. Extension 40 has a generally smooth or even lower inclined surface 42 (see FIGURES 4 and 5) and an outer annular bead or boss 44. Lower cup-shaped member 38 has an annular rim 46 with an annular lip 48 formed on its inner circumference. Beneath lip 48 is a lower annular channel or groove 50 formed in the inner wall of rim 46 and defining a seat surface 52.

Body members 36 and 38 are designed so that the lower cylindrical end of body member 36 will coaxially telescope into the open rim 46 of cup-shaped member 38 and bead 44 will snap under annular lip 48 and be held in position by contact with seat surface 52. The interfitting of body members 36 and 38 requires a resilience when the members are napped together. One material which furnishes the necessary resilience is plastic, such as, for example, an acetal resin. It is to be understood that other types of plastics or resilient materials may be employed for forming body members 36 and 38. Annular lip 48 and head 44 are designed such that the rim of member 38 must expand by a flowing of the plastic material to permit bead 44 to enter and snap into groove 50 against seat 52. Bead 44 is of a diameter slightly larger than the diameter of lip 48 so that there is a tight fit between the two because of the mismatch. A lower inclined shoulder 54 at the bottom of annular rim 46 forms a generally even surface within cup-shaped member 38 and extends in a direction generally parallel to surface 42 on annular extension 40.

A flexible thin circular pump diaphragm 56 is fitted along a marginal portion 55 on annular shoulder 54 formed within cup-shaped member 38. When bead 44 is snapped into annular groove 50, lower flat surface 42 on annular extension 40 presses against marginal portion 55 to force diaphragm 56 tightly against shoulder 54. Diaphragm 56 is of any appropriate material such as a fabric coated with a fuel resistant synthetic rubber material to provide suflicient flexibility and strength.

A fuel pumping chamber 57 is formed between diaphragm 56 and lower cup-shaped member 38 while a substantially closed air chamber 58 is formed within upper cup-shaped member 36. Positive pressures in intake manifold M are relatively small and variable when the pump is utilized with a four cycle engine. Thus, a coil spring 59 is positioned within an annular groove 60 of body member 36 to form a seat for one end of spring 59. The other opposite end of spring 59 fits in a dished plate 61 supported on diaphragm 56. Spring 59 drives the pump while providing a uniform pumping stroke and is loaded by the negative pressures in the intake engine manifold which are sufiicient to fully load the spring. Diaphragm 56 bottoms on a ledge 62 forming the bottom of pumping chamber 57 as shown in FIGURE 3 and merging with inclined seat surface 54. At the end of a discharge stroke diaphragm 56 is generally flattened out against ledge 62 and merging surface 54 as shown in FIGURE 3. Surfaces 42 and 54 by being flared or inclined around 30 with respect to the horizontal axis of pump 12 result in the formation of a looped diaphragm which flexes sufliciently to follow the adjacent surfaces defining pumping chamber 57 and air chamber 58 without any substantial stretching of the diaphragm. This does not tend undesirably to stress or distort the diaphragm. Nipple 16 extends laterally from the top of cup-shaped member 36, where nipple 20 extends laterally from the bottom portion of cup-shaped member 38. Nipple 16 is formed with a passage 63 therethrough which connects an air chamber 58 with flexible tubing 14 to manifold M of the engine. In a similar manner, a fuel inlet passage 64 extends through nipple 20 to connect pumping chamber 57 with fuel line 22 leading from the fuel tank 24.

An inlet valve structure 66 is inserted in a short portion of passage 64 leading into chamber 57 and in a similar manner an outlet valve structure 68 is fitted within a short outlet passage through the bottom of cup-shaped member 38 connecting chamber 57 with an outlet chamber 70.

Valve structures 66 and 68 are identical and each consists of a small triangular-shaped disk 72 made of a synthetic fuel resistant material, such as an acetal resin. Disk 72 is seated on an annular rib 74 and retained in position by a C-shaped metal snap ring 76. The valves are easily mounted within the pump structure by first inserting each triangular-shaped disk 72 and then snapping the associated C-ring 76 in position adjacent disk or valve 72. The tendency of C-ring 76 to expand outwardly urges ring 76 to engagement with the adjacent wall surface thereby to hold ring 76 in position. The head and groove arrangement 44 and 50 permit a fueltight connection. Cup-shaped members 36 and 38 are coaxially mounted with matching cylindrical portions fitted together. This permits one member to be rotated relative to the other member about the common longitudinal axis of pump 12 to provide any desired angular relationship between inlet nipple 20 and air nipple 16 thereby allowing adaptation of the pump to any carburetor or any engine installation.

Projecting from carburetor 10 is an apertured boss 80 extending upwardly from the body of Carburetor 10. Boss 80 fits within sleeve 82 and permits cup-shaped body member 38 to move relative to carburetor 10 to permit relative rotative movement.

Referring now particularly to FIGURES 4 and 5 and constituting an important feature of the invention, surface 42 forming the lower face of annular extension 40 is interrupted intermediately thereof by an annular groove 84. Joining surface 42 at pointed corners 86 are surfaces 88 and 90 which define groove 84 and join each other at apex 92 to form an angle of 90. Interrupting surface 54 is an annular groove 94. Defining groove 94 are surfaces 96 and 98 which join surface 54 at relatively sharp corners 99 and join each other at apex 100 while forming an angle of 90 therebetween. Apices 92 and 100 are preferably aligned in a direction generally parallel to the longitudinal axis of pump 12. Surfaces 42 and 54 which are generally parallel slope at an angle of around 30 with respect to the transverse axis of pump 12. Thus, marginal portion 55 of diaphragm 56 is gripped between sloping surfaces 42 and 54 to direct diaphragm 56 downwardly into pumping chamber 57. Force i exerted by surfaces 42 and 54 against marginal portion 55 in a direction generally parallel to the longitudinal axis of pump 12 and the section of diaphragm portion 55 extending across grooves 84 and 94 is distorted or swelled to form bulges 102 and 104 extending or protruding into grooves 84 and 94, respectively, thereby forming a bulge on each side of diaphragm 56. It is to be noted that bulges 102 and 104 are offset with respect to the upper and lower surfaces of diaphragm 56.

Opposing surfaces 42 and 54 are smooth and have no projections thereon for bulging the diaphragm. A pressure or force on each side of each groove 84 or 94 causes the diaphragm to swell into the adjacent groove and this prevents the diaphragm from being pulled from between surfaces 42 and 54. The relatively sharp or pointed corners 86, 99 tend to bite into the resilient diaphragm to effect flowing of the diaphragm material into the grooves 84, 94 and to grip tightly the diaphragm. A fluid-type seal is effected by the bulges 102, 104. The lower inner edge of extension 40 is beveled at 106 so that diaphragm 56 has a smooth surface to fit against on its intake stroke.

It is to be understood that the body members forming pump 12 may be formed with the upper cup-shaped body member receiving a lower cup-shaped body member in telescoping interfitting relation such as disclosed in aforementioned patent application Serial No. 220,638. Further, while the present invention has been illustrated as employed with fuel pumps it is to be understood that the diaphragm device may be utilized whenever it is desired to grip or clamp the diaphragm between two opposed surfaces to provide a securing means for the diaphragm as well as a sealing means. For example, the diaphragm device may be utilized with air motors, pressure switches, and other devices employing a diaphragm clamped between two opposed members.

While the fuel pump has been illustrated as utilized with a four cycle internal combustion engine, it is to be understood that the present invention may be utilized with a two cycle internal combustion engine and may be attached directly to the crankcase. When utilized in two cycle operation, the spring for driving the diaphragm (spring 59 of FIGURES 2 and 3) ,is normally not employed as air pressure pulsations created in the crankcase by movement of the piston backward and forward provide sufficient positive pressure for driving the pump.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results obtained.

As various changes could be made in the above construction without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim:

1. A diaphragm device comprising a pair of interfitting body members, one of said body members being cupshaped and having an outer annular rim and an annular seat adjacent said rim, the other of said body members having an annular extension received within the annular rim of the cup-shaped member, said annular seat and said annular extension having complementary oppositely facing generally smooth and parallel surfaces each interrupted intermediately thereof by an annular groove, a generally circular diaphragm positioned across and having its marginal portion extending between the oppositely facing surfaces of said annular seat and said annular extension across the annular grooves thereof, the portion of the diaphragm spanning the grooves being deformed into both of said grooves by pressing of the diaphragm between the generally smooth and parallel surfaces of the annular seat and annular extension, and means to hold the body members in interfitting relation for gripping the diaphragm therebetween, said generally smooth and parallel surfaces sloping downwardly from the outer periphery of the diaphragm to form an inclined seat for the marginal portion of the circular diaphragm, said annular grooves being generally oppositely arranged with respect to the longitudinal axis of the device and a bulge on each surface of the diaphragm being received within the adjacent groove' thereby to grip and seal the diaphragm along its marginal portion.

2. A diaphragm device comprising a pair of interfitting molded plastic body members, one of said body members being cup-shaped and having an outer annular rim and an annular seat adjacent said rim, the other of said body members having an annular extension received within the annular rim of the cup-shaped member, said annular seat and said annular extension having complementary oppositely facing generally smooth and parallel surfaces each interrupted intermediately thereof by an annular groove, a generally circular diaphragm positioned across and having its marginal portions extending between the oppositely facing surfaces of said annular seat and said annular extension and spanning the annular grooves thereof, the portion of the diaphragm across said grooves being deformed into both of said grooves upon pressing of the diaphragm between the generally smooth and parallel surfaces of the annular seat and annular extension, and an interfitting annular lip and groove arrangement on said annular extension and annular rim whereby said body members may be snapped together to effect the interfitting 6 of the lip and groove arrangement and gripping of the diaphragm between the body members, said lip and groove arrangement permitting relative rotative movement between the body members while holding the body members together in pressed relation against the diaphragm.

3. A diaphragm device as set forth in claim 2 wherein a nipple is positioned on one cup-shaped body member and an inlet and outlet are positioned on the other body member telescoped within said cup-shaped body member.

4. A diaphragm device as set forth in claim 2 wherein said lip and groove arrangement comprises an annular lip on the outer circumference of the annular extension and a groove on the inner circumference of the annular rim adapted to receive said lip in interfittting relation.

5. A pulse pump for fuel system, said pump comprising a pair of interfitting cup-shaped body members, one of the body members having an annular rim and an annular shoulder adjacent the rim forming a seat, the other of said body members having an annular extension telescoping within the first mentioned cup-shaped member and adapted to be disposed adjacent said annular shoulder, said annular shoulder having a generally smooth and even surface interrupted intermediately thereof by an annular groove, said annular extension having a projecting outer generally smooth surface generally parallel and complementary to the surface of said annular shoulder and in terrupted intermediately thereof by an annular groove, said anular grooves arranged generally opposite each other with respect to the longitudinal axis of the pulse pump, a generally circular diaphragm sealed along a marginal portion between the annular extension and the annular shoulder to form an air chamber with one body member and a fuel chamber with the other body member, the marginal portion of the diaphragm extending across said grooves and being deformed into the grooves by pressing of the diaphragm between the generally parallel surfaces thereby to grip and seal the diaphragm thereat, an annular lip on the outer surface of the annular extension, and a recess on the inner surface of the annular rim receiving the lip and holding the body members together in pressed relation against the diaphragm, the body member forming the air chamber having a first nipple for connection. to a source of air pulsations and extending outwardly therefrom away from the common axis of the body members, the body member forming the fuel chamber having inlet and outlet passages and a second nipple extending outwardly away from said common axis of the body members.

6. A pulse pump for a fuel system as set forth in claim 5 wherein said second nipple includes a portion of the fuel inlet passage and said body members are rotatable relative to each other about said common axis while the body members are held together by said annular lip and recess, the common axis of the body members being substantially normal to the longitudinal axes of the nipples thereby to permit the nipples to be easily connected to fuel and air sources.

7. A pulse pump as set forth in claim 6 wherein said first mentioned cup-shaped body member forms the air chamber and said other cup-shaped body member forms the fuel chamber.

8. A diaphragm device comprising a pair of interfitting body members, one of said body members being cupshaped and having an outer annular rim and an annular seat adjacent said rim, the other of said body members having an annular extension received within the annular rim of the cup-shaped member, said annular seat and said annular extension having complementary oppositely facing generally smooth and parallel surfaces each interrupted intermediately thereof by an annular groove, a generally circular diaphragm positioned across and having its marginal portion extending between the oppositely facing surfaces of said annular seat and said annular extension across the annular grooves thereof, the portion of the diaphragm spanning the grooves being deformed into both of said grooves by pressing of the diaphragm between the generally smooth and parallel surfaces of the annular seat and annular extension, said generally smooth and parallel surfaces sloping inwardly from the outer periphery of the diaphragm to form an inclined seat for the marginal portion of the circular diaphragm, the annular grooves each defined by surfaces joining the respective smooth parallel surfaces along generally pointed corners and being aligned generally along the longitudinal axis of the device but being slightly oiTset from each other so that said generally pointed corners aid in pressing an adjacent portion of the diaphragm into the respective oppositely facing groove thereby to grip and seal the diaphragm thereat, and means to hold the body members in interfitting relation for gripping the diaphragm therebetween.

9. A diaphragm device as set forth in claim 8 wherein said generally smooth and parallel surfaces slope inwardly at an angle of around 30 with respect to the transverse axis of the device.

10. A diaphragm device comprising a pair of interfitting molded plastic generally cup-shaped body members, one of the body members having an outer annular rim and an annular shoulder adjacent the rim forming a seat, the other of said cup-shaped body members having an annular extension telescoping within the first mentioned cup-shaped member and adapted to be disposed adjacent said annular shoulder, said annular shoulder and said annular extension having generally parallel oppositely facing generally smooth surfaces, a first annular groove arranged intermediately of said annular shoulder, a second annular groove arranged intermediately of the smooth surface on said annular extension generally opposite said first annular groove, a generally circular diaphragm having its marginal portion extending between said surfaces and across the grooves therein, an annular lip on the outer surface of said annular extension and a complementary annular recess on the inner surface of said annular rim receiving said lip and pressing the body members together against the diaphragm when the annular extension is pressed in telescoped relation within said rim thereby to deform said diaphragm into both of said grooves for gripping and sealing the diaphragm thereat.

References Cited by the Examiner UNITED STATES PATENTS 2,786,419 3/1957 Lynn 10344 FOREIGN PATENTS 873,601 7/1942 France.

LAURENCE V. EFNER, Primary Examiner.

ROBERT M. WALKER, Examiner. 

1. A DIAPHRAGM DEVICE COMPRISING A PAIR OF INTERFITTING BODY MEMBERS, ONE OF SAID BODY MEMBERS BEING CUPSHAPED AND HAVING AN OUTER ANNULAR RIM AND AN ANNULAR SEAT ADJACENT SAID RIM, THE OTHER OF SAID BODY MEMBERS HAVING AN ANNULAR EXTENSION RECEIVED WITHIN THE ANNULAR RIM OF THE CUP-SHAPED MEMBER, SAID ANNULAR SEAT AND SAID ANNULAR EXTENSION HAVING COMPLEMENTARY OPPOSITELY FACING GENERALLY SMOOTH AND PARALLEL SURFACES EACH INTERRUPTED INTERMEDIATELY THEREOF BY AN ANNULAR GROOVE, A GENERALLY CIRCULAR DIAPHRAGM POSITIONED ACROSS AND HAVING ITS MARGINAL PORTION EXTENDING BETWEEN THE OPPOSITELY FACING SURFACES OF SAID ANNULAR SEAT AND SAID ANNULAR EXTENSION ACROSS THE ANNULAR GROOVES THEREOF, THE PORTION OF THE DIAPHRAGM SPANNING THE GROOVES BEING DEFORMED INTO BOTH OF SAID GROOVES BY PRESSING OF THE DIAPHRAGM BE- 